Gas well liquid recovery

ABSTRACT

A gas operated, submersible pumping system, is disclosed as being capable of recovering well fluids below ground surface from a natural gas production well and is adapted to be coupled to flexible continuous metal conveyance conduits. The system includes a housing constructed of a corrosion resistant material; gas inlet and output ports for accommodating respectively higher and lower pressures; well fluids inlet and outlet ports; an internal gas logic switching valve to control pumping action; and a pneumatic mechanical amplifier piston, which isolates gas from liquids, and transfers lower pressure gas into higher pressure liquid discharge pressure, wherein the submersible pumping system is operable between a refill and discharge mode so as to recycle inlet well gas back into the production well without substantially reconstituting the well gas.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing of U.S. ProvisionalPaten Application Ser. No. 60/543,132, entitled “Down well PneumaticSubmersible Pump With Built-In Mechanical Pressure Amplifier AndPumping”, filed on Feb. 9, 2004, which is incorporated herein byreference.

TECHNICAL FIELD

The present invention relates generally to sub-surface fluid recoverypumping systems for natural gas “Stripper” or older production wells.More particularly, this invention is directed to a pneumaticdisplacement method of low volumes of well fluids from low pressurenatural gas production wells. Specifically, this invention is directedto the provision of a method and apparatus for pneumatic displacementpumping, incorporating flexible metal continuous piping conveyance lines(e.g., unspoiled tubing), a low volume timer-less sub-surface pneumaticpump, and a compressed gas source that cooperates to cause the down-wellpump to remove all types of well liquids entering an older natural gasproduction well.

BACKGROUND

A problem facing today's well operators of natural gas “Stripper”production wells is that the available pumping systems of today arecosting more to operate and maintain than the benefit they provide.Recently the United States Department of the Interior gave “Stripper”well operators a royalty rate reduction to encourage operators not toabandon their non-profitable “Stripper” wells. The main reason for thissituation is today's pumping systems were not designed for “Stripper”well conditions. That is low fluid volume recovery, low well pressure,and low production volume. The most popular and most available pumpingsystem today is the “Rod Pump” or Pump Jack” type pumping system. Thistechnology was originally design for high volume fluid removal in highvolume production wells. Operators today have made many modifications tothis equipment over the years to adapt to dwindling fluid recovery anddwindling production volumes. Even with the many modifications, the “RodPump” or Pump Jack” type pumping method is neither cost effective in itsdaily operations, nor its method of retrieval. Other significantproblems facing the “Rod Pump” or Pump Jack” type pumping method isabove ground air pollution, noise pollution, and visual pollution. Allof these problems need to go away if “Stripper” wells are to be keptproducing. Specifically, pumping systems which consume high quantitiesof an energy resource to operate, remove well fluids on an intermittentbasis, and use rigid segment pipe as their fluid discharge pipe are nolonger cost effective in the “Stripper” well industry. Finally, other“Rod Pump” problems include vapor locking of the pump, sucker rodswearing holes in the production piping, sucker rods getting stuck in theproduction piping all of which require a very expensive and timeconsuming work over rig to pull the rod pump out of the well.

When natural gas production wells begin to fill up with formation fluidssuch as brine water or crude oil distillates, the flow of natural gasdiminishes. Some form of fluid removal on a daily basis is usuallyrequired on most natural gas production wells. When production wellfluid removal volumes drop to a few barrels per day, the present mostcommon “Rod Pump” or “Pump Jack” pumping systems have to revert tointermittent operation due to their high capacity pumping design.Intermittent recovery of production well fluids creates a substantialloss or complete stoppage of produced natural gas. U.S. Pat. Nos.6,497,561 to Skillman, and 5,104,301 to Brewer each disclose rod pumptype devices for recovering well fluids from a natural gas productionwell.

Another pumping method giving the “Stripper” well operators problems isthe “plunger lift” pumping system. U.S. Pat. Nos. 6,467,541 to Wells and4,211,279 to Isaacks each disclose “plunger lift” type devices forrecovering well fluids from a natural gas production well. This pumpingsystem has reduced above ground equipment and does not require an energysource for consumption to operate. However, it still recovers well fluidvery intermittently and uses rigid pipe as its fluid recovery conduit.This pumping system also has a regular problem where the metal plungergets stuck in the production piping requiring the piping to be pulledfrom the well.

Yet another method in fluid recovery of natural gas production wellsutilizes a hydraulically driven down-well pump with an above groundelectrical drive motor pumping system. U.S. Pat. Nos. 6,454,010 toThomas et al is a good example of a pumping system that consumes themost expensive type of energy and requires an excessive amount materialsfor operations and servicing. High pressure hydraulic fluid flow iscreated from an above ground electrically driven pumping system that isused to power the sub-surface well fluids pumping system. This pumpingsystem requires Electricity which is the most expensive energy resourceavailable. Furthermore, Thomas et al invention is very high in materialconsumption due to its multiple down-well motors, pumps, pipingconduits, and an above ground pumping system. This invention alsoexposes the production well to possible foreign hydraulic fluids whenthe system has a leak or breakage in its piping.

Still another method in fluid recovery of natural gas production wellsis a down-well electrically driven pump. U.S. Pat. No. 6,550,535 toTraylor is a good example of an another pumping system that consumes themost expensive type of energy available and utilizes rigid piping forits discharge fluids conduit. Down well electrically driven pumpscommonly require three phase electric power to lift water fromproduction well depths. This source of power is very unpredictable in itdelivery. It is common knowledge that one of the three phases are beingdropped or lost on a regular basis. When this happens the electric motorin the down-well pump is damaged enough to require the pump to beremoved and motor repaired.

What is needed is a way to remove liquid from a gas well thatsubstantially overcomes the above problems.

SUMMARY

In one implementation, an apparatus includes pneumatic means, down awell and driven by gas from the well, for driving hydraulic means, alsodown the well, for expelling liquid from the well. In thisimplementation, at least one of the pneumatic or hydraulic means can bein fluid communication with the surface of the gas well through tubing,such room temperature flexible tubing or unspooled tubing, etc.

In another implementation, a pneumatic pump in a gas well is driven bycompressed gas from the gas well, and drives a hydraulic pump in the gaswell to pump liquid from the gas well.

Compressed gas from the gas well can be used to drive the pneumaticmeans or pneumatic pump in the foregoing implementations, respectively.

In a still further implementation, gas pumped from the pneumatic meansor pneumatic pump in the foregoing implementations, respectively, can beused to drive the hydraulic pump or hydraulic means, respectively, topump liquid from the gas well.

In yet another implementation, liquid is removed from a gas well with ahydraulic pump by driving a hydraulic pump with the gas that is outputby the pneumatic pump.

In any of the foregoing implementations, the pneumatic pump, thepneumatic means, the hydraulic pump, or the hydraulic means can be influid communication with a container to contain the conveyed fluid onthe surface of the gas well through continuous tubing, such as unspooledtubing.

In a still further implementation, a well casing extends through adrilled bore in the earth to a natural gas bearing earth formation whichwell casing may be provided with a well head at its upper extremity andwith a perforated element, typically referred to as a screen, at itslower extremity. Formation fluids, typically referred to as productionfluid, may be forced by formation pressure, either induced naturally orartificially and may enter the well casing through the perforations ofthe screen and may rise to a level within the casing.

At the surface a natural gas compressor may be provided with an inletconduit from the well head for flow of low pressure well gas to thecompressor and an outlet conduit from the compressor for flow of highpressure well gas to a sales conduit and to the inlet of a surfacechemical treatment apparatus. At the surface a flexible small diametermetal conduit may be provided from the outlet of the surface chemicaltreatment apparatus over to the well head and connected to the down-wellgas supply conduit for flow of chemically treated high pressure well gasdown to the sub-surface pump. At the surface a fluid discharge holdingtank inlet is connected to the well head fluid discharge outlet forflowing sub-surface well fluids to an above ground tank.

In the well a first removably suspended flexible metal gas supplyconduit may be provided with a load bearing and well head sealingadapter that is attached to the well head at the surface and aconnecting adapter at the bottom below the production zone within thecasing to connect to the gas inlet port of the pump. Also in the well asecond removably suspended flexible metal fluid discharge conduit may beprovided with a non load bearing and well head sealing adapter that isattached to the well head at the surface and a connecting adapter at thebottom below the production zone within the casing to connect to thefluid discharge port of the pump. Also, in the well a third removablysuspended flexible metal exhaust gas conduit may be provided just abovethe fluid level in the well and at the bottom below the production zonewithin the casing to connect to the exhaust gas port of the pump.

All conduits may be provided a clamping apparatus to prevent conduitdamage upon installation into the well casing.

A pneumatic pump provided within the well casing and located below theproduction zone includes a pneumatic switching valve with an inlet andseveral outlets for flowing treated high pressure well gas to thepneumatic piston chambers. A pneumatic pump chamber with two two-wayflow passages for flowing treated high pressure well gas to the top andbottom sides of the pneumatic portion of the pump piston. A pump pistonthat transfers the treated high pressure well gas energy into a veryhigh liquid discharge energy. A liquid pump chamber with a filteredinlet for flow of well fluid into the liquid pump chamber from thecasing. A solids collection apparatus connected to the liquid pumpchamber for preventing the plugging of the pump outlet. A first conduitthat connects the gas supply inlet of the pump to the above ground gascompressor outlet. A second conduit that connects the outlet of thesolids collection apparatus to the above ground fluid dischargecollection tank. A third conduit that connects the gas exhaust outlet ofthe pump to a check valve positioned a few feet above the well casingfluid level.

Advantageously, any of the foregoing implementation can be operated soas to avoid substantially consuming or destroying the well gas such thatsubstantially only compressed energy within compressed well gas isconsumed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the implementations may be had byreference to the following detailed description when taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a sectional view of a well casing extending through a wellbore in the earth's surface to an natural gas bearing earth formationand also illustrating in simple mechanical terms the provision of apneumatic displacement type pump mechanism constructed in accordancewith an exemplary implementation within the casing structure in positionfor pumping production fluid from the well;

FIGS. 2-5 are respective elevation cross-sectional views of an exemplaryimplementation, where FIGS. 2 and 5 show a snap shot in a cycle in whichliquid is being drawn from the well, and where FIGS. 3 and 4 show a snapshot in a cycle in which liquid is being expelled from the well.

DETAILED DESCRIPTION

Specific embodiments and variations of the invention will now bedescribed. These embodiments are exemplary in nature, and not intendedto limit the invention or its applications. For instance, while anapplication is discussed for fluid removal from a natural gas productionwell, implementations may also be utilized for displacement of otherfluids that may or may not be located within the earth formation.Moreover, while an application is discussed for the removal of wellfluids in a natural gas well with low fluid removal, it is in no wayintended that such discussion will limit the invention solely to use inconnection with fluid removal from an older or “Stripper” natural gasproduction well.

In various embodiments, a system and pumping technology provide pumpingof very deep well fluids from the bottom of a natural gas productionwell. This system can include: a low pressure well gas coming out ofwell into an above ground gas compressor; high pressure well gas flowingfrom gas compressor to a first flexible continuous metal conduit; highpressure well gas flowing through a conduit down to inlet port of apneumatic pump; high pressure well gas entering an internal logicswitching valve which sends high pressure well gas into an internalmechanical amplifier piston chamber of the pneumatic pump; and a logicswitching valve that exhausts low pressure compressed gas out through anexhaust port of the pneumatic pump back into well. A pneumaticmechanical amplifier piston movement creates high pressure internalliquid pumping action in a lower liquid pumping chamber of a hydraulicpneumatic pump and the well fluids enter the bottom inlet of thehydraulic pump. Well liquids are ejected out of the top of the hydraulicpump through the liquid discharge port of hydraulic pump. Dischargedliquid from the hydraulic pump flow upward to the surface in a secondflexible continuous metal conduit. The low pressure well gas coming outof the production well is compressed by an above ground gas compressor.A substantially small amount of the compressed gas is sent back down tothe sub-surface pneumatic pump, and is recycled back into the productionwell.

Referring now to FIG. 1, there is depicted in partial section a typicalearth formation having a well bore drilled and casing 1 inserted with aperforated section 1A at the intersection relation with a natural gasbearing stratum of the formation, an above ground well head 3 connectedto the well casing 1A, an above ground well liquids holding tank 14, anabove ground natural gas compressor 5, an above ground gas pressureregulator apparatus 7, an above ground gas oil treatment apparatustreatment 8 and 8 a. The natural gas compressor 5 draws high volume, lowpressure natural gas from the well head 3 thru a pipe conduit 4 andejects high volume high pressure natural gas out thru pipe conduit 6 to“Sales” or pipeline meter and low volume high pressure gas out to thegas regulator 7. Gas pressure regulator 7 is adjusted to deliveradequate pressure to cause sub surface pump 24 to lift well fluids tothe surface at a desired flow rate. Pressure regulated gas flows intothe top of the gas oil treatment apparatus 8 and thru the bottom gas oiltreatment apparatus 8 a causing the pressure regulated gas to transportoil to the sub surface pump 24 for internal lubrication of moving parts.A small diameter flexible metal conduit 9 is connected between theoutlet of the gas oil treatment apparatus 8 a and to the first down wellsmall diameter flexible metal conduit 17 coming out of the well head “Y”port 10. Another small diameter flexible metal conduit 13 is connectedbetween the outlet of the well fluids holding tank 14 and to the seconddown well small diameter flexible metal conduit 16 coming out of thewell head second conduit support clamp (slips) 12 at the top of the wellhead 3. The support clamp (slips) is the primary support for down wellconduits 16, 17 and pump 24. Just below the support clamp (slips) 12 isa sealing apparatus (packoff) 11 to prevent well gas from escaping thewell head 3. Just below the sealing apparatus (packoff) 11 and below thewell head flange plate is a control shutoff valve 15 for isolating thewell.

Suspended from the well head 3 are conduits 16 and 17 which extend downthe well casing and connect to the top of pump 24. These conduits areattached together every 100 feet with a metal clamp 18. First conduit 16connects to the gas inlet port 30 in FIG. 2 and second conduit 17connects to the top of the outlet of the solids trap 20.

In the well casing the two conduits are joined together with a clamp 18about every 100 feet over the entire length of these conduits. Softnylon guides 22 are attached to the solids trap 20 to guide the pump 24up and down the well casing 1. Small conduit 23 flows well fluids up andinto the top of the solids trap 20. The bottom of the solids trap 20 isrigidly connected to the top of the pump 24. The inlet particle filter25 is rigidly connected to the inlet of the pump 24.

Referring now to the drawing in which there is shown in FIG. 2 a pump 24in accordance with the present invention. As shown in FIG. 2 of thedrawings, I represents the top segment of pump 24 comprising a solidcylindrical body of material not susceptible to corrosion such as 316stainless steel housing a gas switching valve 32 a and gas switchingvalve sleeve 32 b, gas exhaust port 31, gas supply port 30 and liquiddischarge port 43. II represents the upper piston segment of pump 24comprising a solid cylindrical body of material not susceptible tocorrosion such as 316 stainless steel and housing a gas metering valve33, a gas switching valve 34 and upper piston 36 support channel. IIIrepresents the mechanical amplifier piston housing of pump 24 comprisinga solid cylindrical body of material not susceptible to corrosion suchas 316 stainless steel and housing the pneumatic mechanical amplifierpiston 36. IV represents the bottom segment of pump 24 comprising asolid cylindrical body of material not susceptible to corrosion such as316 stainless steel and housing the ceramic liquid sleeve 38 and ceramicpiston head 39, inlet check valve plug 40, inlet check valve plughousing 41, and a backflow discharge check valve 42. As can be seen,upper piston 36 has a significantly larger surface area than piston head39, and a rigid member separates pistons 36, 39 are separated by a fixeddistance.

OPERATION

Low Pressure well gas entering the well casing 1A from the formation isdrawn upwards by the above ground gas compressor 5. This low pressurewell gas enters gas compressor 5 thru conduit 4 which is connected towell head 3. This low pressure well gas is then split into two internalflow paths, the first path provides well gas for the compressor engineto operate and the second path is compressed and high pressure well gasis ejected out of the gas compressor 5 thru conduit 6 to “Sales” and topressure regulator 7. The regulated well gas is split into two flowpaths. The first flow path passes into the top of the oiler 8 to providea balance of pressure inside the oiler 8. The second flow path passesthrough a tee at the base of the oiler 8 a where oil is dripped into thegas flow. The regulated and oiled gas flows through conduit 9, subsurface conduit 17, and into pump 24 gas inlet GA of FIG. 2.

FIG. 2 shows the pump 24 in the maximum liquid filling state. In FIG. 2,gas flows into pump 24 through GA. Gas flows from GA through switchingvalve 32 a in segment I, out through channel GB to switching valve 34,and out to channel GE via hidden channel. Gas flows through channel GEinto chamber GF of segment III causing the pneumatic mechanicalamplifier piston 36 to travel upwards. When piston 36 reaches the top ofchamber GF, piston 36 depresses switching valve 34 causing the gas inchannel GB to flow through channel GC and into chamber GD. Gas flowsinto chamber GD forces switching valve 32 a upward. Gas also flows fromchamber GF through channel GG into channel GH and out of the pump 24 atGI. Well liquids enter the pump 24 through LA, flow through inlet checkvalve body 41, around check valve plug 40 and into pumping chamber LB.

FIG. 3 shows the pump 24 in the liquid emptying state. In FIG. 3, gasflows into pump 24 through GA. Gas flows from GA through switching valve32 a in segment I, out through channel GB to chamber GC in segment III,causing pneumatic mechanical amplifier piston 36 to travel downward.Travel of the pneumatic mechanical amplifier piston 36 causes ceramicpiston head 39 to also travel downward discharging well liquids inchamber LA in segment IV, out through channel LB, up through backflowdischarge check valve 42, up through channel LD, and out through LE. Gasalso flows out of chamber GD, through channel GE, up through channel GF,and out through GG.

FIG. 4 shows the pump 24 in the switching travel direction state. InFIG. 4, gas flowing through needle valve 33, through channel GE and outthrough GF causes switching valve 32 a to travel downward.

FIG. 5 shows the pump 24 in the liquid filling state. In FIG. 5, gasflows into pump 24 through GA. Gas flows from GA through switching valve32 a in segment I, out through a hidden channel into channel GB, andinto chamber GC causing piston 36 to travel upwards. Gas also flows fromchamber GD through channel GE, through channel GF, and out through GG.Well liquids enter pump 24 at LA and flow through inlet check valve body41, through inlet check valve plug 40, and into chamber LB.

The seals material in the hydraulic and pneumatic pumps can be made fromViton® or glass filled Teflon®. The pistons in the hydraulic andpneumatic pumps can be ceramic. The in-board gas switching spool valve32 can be made of a graphite filled nylon.

The sub surface pump 24 can internal metal parts made of non-corrosivematerials, for instance 316 stainless steel. The sub surface pump 24 canbe made to have dimensions of about 3.50 inches diameter by 13 inchestall, weighing about 40 lbs. The power ratio of the pneumatic tohydraulic pumps can be about 1:11.

In one embodiment, the materials for the tubing 16, 17, and 26 can becontinuous metal tubing that is flexible around room temperature. Forinstance, the tubing can be unwound from a spool prior to insertion inthe well during installation. The tubing used in the well for the gassupply and for the liquid discharge can be about ⅜ inch diameter 2205duplex stainless steel, which is available from WebCo Industries in SandSprings, Okla.

By way of example, and not by way of limitation, for a natural gasproduction well of a depth of about 3000 feet, one implementationassumes that the compressed gas supply is about 170 psi, the well casingpressure is about 20 psi, the well diameter is at least 4 inches, andthe well fluids viscosity is relatively low. In this case, well liquidsat 3000 feet create a back pressure weight at the outlet of the pump ofabout 1299 psi, which is calculated as: 3000 feet/2.31 feet/psi=1298.70psi. Such an embodiment of the sub surface pump 24 can lift well liquidsfrom the depth of 3000 feet deep when the gas supply pressure at theinlet of the sub surface pump 24 can is at least 140 psi and the wellcasing pressure is not more than 20 psi. The working supply pressure, atthe inlet gas supply-well casing, is about 120 psi, which is calculatedas: 140 psi (e.g., pressure of the compressed gas) −20 psi (e.g., thepressure within the casing). The pump liquid discharge pressure iscalculated as: working supply pressure×power ratio, which here is: 120psi×11=1320 psi.

Disclosed above are implementations of a displacement type pumpingmechanism that provides the capability of liquid displacement pumping ofa production liquid from an earth formation. These implementations, allor individually, can provide:

-   -   (i) fluid recovery that minimizes energy and material resources        consumption;    -   (ii) a pneumatic displacement pump that is controllerless,        compact, and operates off of low pressure natural gas, and that        will not substantially consume or damage the well natural gas        but rather can recycle the well gas supplied to the pump back        into the production well after use;    -   (iii) little or no above-ground negative esthetic visual        effects, air pollution, or noise pollution;    -   (iv) an apparatus that places gas and/or liquid pumps in fluid        communication with the surface of a well through flexible        continuous metal piping that can be deployed substantially        faster and safer than rigid pipe (for instance, coupled joints),        and that can be installed using substantially smaller rigs with        substantially no possibility of spilling well fluids on the        ground outside the well;    -   (v) a pneumatic displacement type pumping apparatus that can be        used in production wells of relatively small casing dimensions;        and    -   (vi) an allowance for liquid chemicals for paraffin control,        scale control, and hydrostatic fluid pressure control to pass        freely thru the pump and out into the production well fluid.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An apparatus comprising a low pressure pneumatic means, down a welland driven by gas from the well, for driving a high pressure hydraulicmeans, also down the well, for expelling liquid from the well.
 2. Theapparatus as defined in claim 1, wherein at least one said means is influid communication with the surface of the well through flexibletubing.
 3. The apparatus as defined in claim 2, wherein the flexibletubing is selected from the group consisting of: room-temperatureflexible tubing, tubing that is spooled prior to use and unspoiled foruse, stainless steel tubing.
 4. The apparatus as defined in claim 1,further comprising a container for both the pneumatic means and thehydraulic means.
 5. The apparatus as defined in claim 1, furthercomprising: means for removing gas from the well; and compressor means,fired by the gas removed from the well, for compressing the gas from thewell, wherein the gas from the well that drives the pneumatic means isthe compressed gas that is compressed by the compressor means.
 6. Anypneumatic pump in a well, driven by gas from the well, and driving anyhydraulic pump in the well to pump liquid from the well.
 7. Theapparatus as defined in claim 6, wherein at least one of the pneumiticand hydraulic pumps is in fluid communication with the surface of thewell through flexible tubing.
 8. The apparatus as defined in claim 7,wherein the flexible tubing is selected from the group consisting oftubing that is flexible at room-temperature, tubing that is spooledprior to use and is unspoiled for use, and stainless steel tubing. 9.The apparatus as defined in claim 6, further comprising a compressor tocompress the gas removed from the well, wherein the gas driving thepneumatic pump in the well is the compressed gas.
 10. The apparatus asdefined in claim 6, further comprising a container for both thepneumatic pump and the hydraulic pump.
 11. The apparatus as defined inclaim 6, wherein: each of the pneumatic pump and the hydraulic pump havea piston; and the piston of the pneumatic pump is separated by a fixeddistance from the piston of the hydraulic pump by a rigid member. 12.The apparatus as defined in claim 11, wherein the piston of thepneumatic pump has a greater pumping surface area than that of thehydraulic pump.
 13. A method comprising: driving a pneumatic pump in awell with gas from a well to output gas there from; driving a hydraulicpump in the well with the gas output from the pneumatic to thereby pumpliquid from the well.
 14. The method as defined in claim 13, furthercomprising removing the gas from the well prior to driving the pneumaticpump with the gas from the well.
 15. The method as defined in claim 14,further comprising compressing the gas removed from the well, whereinthe gas driving the pneumatic pump in the well is the compressed gas.16. The method as defined in claim 13, wherein at least one of thepneumatic pump and the hydraulic pump is in fluid communication with thesurface of the well through flexible tubing.
 17. The method as definedin claim 16, wherein the flexible tubing is selected from the groupconsisting of: room-temperature flexible tubing, tubing that is spooledprior to use and unspoiled for use, stainless steel tubing.
 18. A methodcomprising: removing gas from a well; compressing the gas removed from awell by a compressor fired by a portion of the gas removed from thewell; driving a pneumatic pump in the well by inputting thereto thecompressed gas; driving a hydraulic pump in the well by inputtingthereto the gas output of the pneumatic pump; and removing liquid fromthe well with the driven hydraulic pump.
 19. The method as defined inclaim 18, wherein the pneumatic and hydraulic pumps are in fluidcommunication with respective containers on the surface of the wellthrough respective flexible tubing.
 20. The method as defined in claim19, wherein the flexible tubing is selected from the group consisting ofroom-temperature flexible tubing, tubing that is spooled prior to useand unspoiled for use, and stainless steel tubing.
 21. The method asdefined in claim 18, wherein the portion of the gas removed to fire thegas fired compressor so as to compress the gas is substantially lessthan the gas removed from the well.
 22. A gas operated, submersiblepumping system, for recovering well fluids below ground surface from anatural gas production well and adapted to be coupled to a flexiblecontinuous metal conveyance conduits thereto, comprising: a housingconstructed of a corrosion resistant material; gas inlet and outputports for accommodating respectively higher and lower pressures; wellfluids inlet and outlet ports; an internal gas logic switching valve tocontrol pumping action; and a pneumatic mechanical amplifier piston,which isolates gas from liquids, and transfers lower pressure gas intohigher pressure liquid discharge pressure, wherein the submersiblepumping system is operable between a refill and discharge mode so as torecycle inlet well gas back into the production well withoutsubstantially reconstituting the well gas.